[PATCH 3/4] mm/secretmem: zeroize secret pages before kdump

[David Hildenbrand (Arm)]

On 7/31/26 18:27, Jan Sebastian Götte wrote:
> Register a CRASH_ZEROIZE notifier that wipes secretmem folios. As a
> result, when CONFIG_CRASH_ZEROIZE is set, secretmem areas will be
> cleared before the kdump kernel is kexec'ed.
> 
> Zeroization runs after the other CPUs have been stopped, so the page
> cache cannot be mutated concurrently and the xarray may be walked
> without taking the i_pages lock. This is a best effort, defense in depth
> measure. s_inode_list_lock is taken with trylock only. If a CPU was
> stopped mid-modification the list may be inconsistent, and this late
> into the panic path, there's nothing we can do about it.
> 
> Signed-off-by: Jan Sebastian Götte <linux at jaseg.de>

Are you actually using secretmem in your use case? I heard some rumors that
secretmem isn't used all that much in practice :)

-- 
Cheers,

David